Public remains ignorant of many causes of cancer

Date: 4/17/2015

“You have cancer” are words that patients likely fear the most to hear. The future instantly becomes uncertain, treatments can be long and exhausting, and the prospect of a life ending far too soon is always present for the patient and his or her family.  

Cancer is a common condition that can affect just about any part of the body, from the skin to the head and neck to blood to multiple internal organs. It is the second-leading cause of death in the U.S., surpassed only by heart disease, and claims nearly 600,000 lives every year.  The American Cancer Society estimates that 1.6 million new cases of the disease will be diagnosed in 2015. And that’s in addition to nearly four million cases of skin cancer.

Despite the prevalence of the disease, most Americans are unaware of the risk factors leading to cancer and what can be done to reduce those risks.  A recent survey of adults by the American Institute of Cancer Research, for example, has revealed that fewer than half of adults know the real risks that can lead to cancer.

Cancer can be described as the abnormal growth of cells in the body, caused either by external factors, such as poor lifestyle choices, exposure to cancer-causing agents, and infections, or internal factors, such as genetic mutation. The human body is composed of trillions of cells, with each growing and replicating itself and constantly repairing damage to the body. Each cell, however, has the potential to start functioning abnormally, to grow out of control, and start spreading and causing disease.  That’s what we call cancer.

With the constant duplication of cells in our body, it is likely that we have cancer cells in our body every day, but the human body has some built-in protections.  Our immune system - a network of cells, tissues, and organs that protects the body from infection – plays an important role in eradicating cancer cells from our body.  

Cancer can develop at any age, but the disease is more common in older people. The Cancer Society, in fact, notes that 78 percent of all cancer diagnoses occur in people 55 years of age and older. Some reasons: our immune system weakens as we get older, our poor lifestyle choices and exposure to environmental factors (such as toxic agents) take their toll as we age, and the diagnosis of cancer often occurs years after exposure to the risks.

While genetics and the inner workings of the human body may be beyond our control, it is important to remember than many cancers can be prevented.  Estimates from such organizations as the U.S. Centers for Disease Control (CDC) and World Health Organization indicate that as many as one-third to two-thirds of cancer cases and deaths can be prevented through lifestyle choices, screenings, and vaccinations.

With that knowledge, here’s how you can reduce your risk of cancer.  

Opt for a healthy lifestyle. Choose a healthy diet with lots of fruits and vegetables and limited amounts of red meat, protect yourself from overexposure to the sun, and avoid excessive alcohol and tobacco in all forms.  Maintaining a healthy weight and regular physical exercise are also critical: The National Cancer Institute, for example, has estimated that up to one-third of cancers are linked to obesity and lack of physical activity.

Get appropriate screenings. Screenings can prevent colorectal, breast, and cervical cancers, which account for nearly 100,000 deaths annually, as well as detect them in their early stages, when treatments are most effective.  The CDC estimates that routine screening can prevent deaths from colorectal cancer by 60 percent.

Get vaccinated. Infections from viruses can also lead to cancer. A vaccine is now available – and recommended for both girls and boys 11 to 12 years of age – to prevent cervical cancer, caused by the human papillomavirus (HPV) that affects 12,000 women and causes 4,000 deaths every year. Other vaccines are available for children and adults to prevent infection from hepatitis A and B, conditions that can lead to liver cancer.

Cancer need not strike the fear that it once did. Therapies are improving, survival rates are increasing, and research studies are constantly finding new links to the disease that result in preventive strategies. The important message to remember is that, for many types of cancer, patients have the power of prevention.

For more information visit www.cancer.org, and for a video discussion, visit www.physicianfocus.org/cancer.

Robb Friedman, M.D., a board-certified oncologist and hematologist, is Medical Director of The Cancer Center at Beth Israel Deaconess Medical Center in Needham, Mass. and an Instructor at Harvard Medical School.  Physician Focus is a public service of the Massachusetts Medical Society. Readers should use their own judgment when seeking medical care and consult with their physician for treatment. Send comments to PhysicianFocus@mms.org.